Feb. 6, 2012 -- A new study finds that Internet dating sites help us get together, but they probably don't make us any luckier in love, despite some companies' claims to the contrary.

"Online dating does present people with tremendous opportunities for dating that have not been available in the past, but there are several drawbacks and limitations that people need to be aware of when they use it," says researcher Harry T. Reis, PhD, a professor of psychology at the University of Rochester, in New York.

The first limitation, Reis says, is that "the kind of mentality people use when they browse through various sites can really affect the value of what they get. The second is that sites that offer costly matching algorithms probably aren't giving people value."

Researchers say that's in large part because companies refuse to disclose how they match clients, saying such information is proprietary.

In a statement emailed in response to the review, eHarmony says it plans to lift the curtain on its methods later this year.

"Full disclosure of intellectual property is a complex process, as it remains one of our central competitive advantages. However, we do recognize an increased desire to better understand how our matching system was created and evidence for its [effectiveness]. We have plans to provide more visibility into our matching algorithms later this year," the statement says.

Is Dating Different if It Starts Online?

The 64-page review, published in the journal Psychological Science in the Public Interest, attempts to chart the impact of online dating on romantic relationships by asking two questions: Is online dating fundamentally different from the ways people have historically met and fallen in love? And does it make dating more successful?

"Those kind of questions haven't been answered," says Jeffrey Hall, PhD, assistant professor in the department of communication studies at the University of Kansas. "People have been really interested for a long time to understand how is Internet dating impacting our lives, but the data is only sort of finally coming to a place where it can be summarized in this way," says Hall, who has studied online dating, but was not involved in the study.

Online dating came to the masses in 1995, when the web site Match.com launched. Back then, only about 4% of couples reported meeting online. Now that number is closer to 23%. That makes online dating the second most popular way singles now get together. The first is a set-up through friends.

Industry analysts say online dating sites now take in about $1 billion annually.

"The difference between what's happened just 15 years ago and now is astounding," Hall says. "We're looking at a sea change in people's attitudes about the role of online dating in our world."

The Problem of Too Much Choice

Reis and his four co-authors, all recognized experts on courtship and dating, found evidence that having many potential partners to consider at the same time changes the way people evaluate their dating choices.

In particular, Reis says, people who have many choices to consider often switch on something called an assessment mindset. In assessment mindsets, people pick things or make decisions by comparing them to their other choices.

The alternative is something called a locomotion mindset, where people make decisions based on whether or not something or someone is likely to help them reach their goals.

Studies of couples have shown that too much assessment leads people to be critical and unsupportive of their partners and pessimistic about the future of their relationships.

The review says that online dating sites foster assessment mindsets and undermine locomotion mindsets. That's not always a great way to find a romantic partner, Reis says.

"It's like going through a catalog and shopping for a pair of pants in the L.L.Bean catalog. Finding a partner is not the same thing. The pants don't smile back at you. The pants don't interact with you to see if your values mesh. You need to take a very different approach."

Does Compatibility Matching Work?

Recognizing that having too many choices may not be a good way to look for a serious relationship, some sites, like eHarmony.com and Chemistry.com, offer to narrow the field.

For a fee, they offer to retrieve potential matches that better align with a client's values, preferences, and in some cases, even their DNA. They also promise that these matches are more likely to result in successful relationships.

But the review finds no evidence to suggest that such matching is scientifically based or lives up to its claims.

That's in large part because dating sites refuse to reveal their methods, saying it would put them at a competitive disadvantage.

"There is no evidence available that meets any standard of scientific validity," Reis says. "Imagine if a drug company came out with a new drug and said that it cures
depression better than any other drug, but refuses to tell people what's in the drug or how they did the study. Would you believe that claim?"

Based on the information they could find, and based on decades of scientific research on love and marriage, researchers say it's unlikely these sites can live up to the happily-ever-after hype.

First, they say, the weight of scientific literature says compatibility between partners who have not met has relatively little power to predict the success of a relationship.

Second, studies have shown that some of the strongest indicators of how long a couple will last depend on how partners interact with each other and how they respond to unpredictable and uncontrollable events -- none of which can be measured before two people even meet.

Advice to Online Daters

Still, online dating can be a useful way to meet romantic partners, Reis says. Here are his suggestions for success:

Don't spend vast amounts of money on it. "The value added by those kinds of matching services is not clear."

When you go through lists of people, only look at a handful at a time. That helps you evaluate each potential partner on his or her own merits, not just on how he or she compares with other people.

Don't just look at the characteristics a person lists on their profile. "Try to imagine, 'What would it be like to go on a hike with this person? What would it be like to go on a vacation with this person?'"

Communicate online, but meet in-person quickly. That keeps online interactions like well-worded emails from taking on undue and unrealistic significance.